body {
    background: #000;
    overflow: hidden;
}

#main {
    background-color: black;
}

canvas {
    display: block;
}

.thunder {
    position: absolute;
    left: 0;
    top: 0;
    right: 0;
    bottom: 0;
    /* 禁用 canvas 上的鼠标和触摸事件 */
    pointer-events: none;
}